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Biomedical subjects

R Kiehl

Publications and source records attributed to R Kiehl.

31 records · Page 2Linked to original sources
PubMed1986

Dose response relationships of anticoagulant activities after subcutaneous administration of two low molecular weight heparins in healthy individuals.

This study was performed to estimate appropriate dosages of two low molecular weight heparins (LMWH) for clinical trials on subcutaneous perioperative thrombosis prophylaxis. Anticoagulatory activities and platelet function were investigated after single doses of two LMWH and of unfractionated sodium heparin (UFH) in 24 healthy individuals. Twelve subjects received subcutaneous injections of 1000, 1500, and 2500 i.u. (aPTT) of LMHW 1, and the other 12 received LMWH 2 at same dosages. The following parameters were determined before 30 min, 1 h, 90 min, 2 h, 3 h, 4 h, 6 h, 8 h, and 10 h after either LMWH or 5000 i.u. (aPTT) UFH: aPTT, thrombin time, anti-Xa activity (S 2222, Coatest heparin), and anti-IIa activity (Chromozym TH). Bleeding time, platelet count, and adrenalin-, collagen-, and ADP-induced platelet aggregation were assessed before and 3 h after administration. After application of 1500 i.u. LMWH 1 and LMWH 2, the anti-Xa and anti-IIa levels were already significantly higher than after 5000 i.u. UFH. 2500 i.u. LMWH 1 and LMWH 2 evoked significantly greater prolongations of aPTT and thrombin time values than did 5000 i.u. UFH. This was not the case after 1000 and 1500 i.u. LMWH. The half-lives of anticoagulatory effects after LMWH were markedly longer than after UFH. Platelet function was not altered by any of the heparins tested. Our results indicate that LMWH cause anticoagulatory effects in vivo that cannot be predicted by in vitro studies and that the appropriate single dosages of LMWH in subcutaneous perioperative thrombosis prophylaxis have to be estimated by dosage determinations in healthy subjects.

Adult↗
PubMed1986

Microcirculation and hemorheology of children with type I diabetes.

A group of 53 children, suffering from diabetes mellitus type I and a group of 12 healthy children were compared. In both groups the following data were determined: Haemoglobin A1C, retinal blood flow (video fluorescence angiography), erythrocyte velocity in finger nailfold capillaries (video capillaroscopy), capillary tortuosity, plasma viscosity, erythrocyte rigidity, and haematocrit. The degree of capillary tortuosity was significantly elevated and erythrocyte velocity was significantly diminished in the group of diabetic children in comparison to the healthy children. Regarding rheological data there was a significant decrease in erythrocyte deformability for the diabetic children. Diabetic children with good stabilization presented better rheological parameters than the poorly stabilized ones. Although these findings provided sufficient information, it will be necessary to cover a long follow up period to judge the prognosis of good and poorly stabilized diabetic children.

Adolescent↗
PubMed1986

Hematocrit as a risk factor for vascular disease.

Besides the classical risk factors for vascular diseases, markedly elevated or reduced hematocrit values may also affect the course of circulatory disturbances. To find out an appropriate hematocrit for sufficient oxygen perfusion of the tissues, several studies have been conducted. Most of the surveys indicate that a hematocrit between 35% and 40% is the best solution. To achieve this aim by iso- and hypervolumetric hemodilution, a clinical double-blind trial with three substances, dextran 40, middle-molecular hydroxyethyl starch and isotonic saline solution was carried out. With regard to clinical results and the possible side effects of dextran middle molecular hydroxyethyl starch seems to be the best choice for hemodilution.

Animals↗
PubMed1985

[Successful treatment of superior mesenteric artery thrombosis with local high-dose urokinase therapy].

A 56 year old man presented with increasing abdominal pain. He suffered from arterial occlusive disease with occlusion of the right A. iliaca communis. Angiography revealed partial thrombotic occlusion of the superior mesenteric artery. Urokinase (UK) at a dose of 150 IU/kg X minutes and heparin (1,000 U/h) was infused through the 7F angiographic catheter for 180 minutes. After 70 min of treatment, angiography showed improvement, and after 120 min the thrombus was nearly completely lysed. A stenosis of approximately 50% was still present after 180 min. Two hours after treatment the patient was pain free without analgesics. Laboratory studies showed systemic fibrinogenolysis, but fibrinogen was still within the upper normal range. Only slight systemic fibrinolytic activity (less than 5 IU UK/ml) could be determined. However, alpha 2-antiplasmin was depleted. The catheter was drawn 15 h after thrombolysis without bleeding. While under concurrent heparin and phenprocoumon therapy, the patient developed an infected gluteal hematoma as a result of i.m. injections prior to this treatment. A repeat angiography approximately one month after thrombolysis revealed further improvement and patency. The patient is well and free of abdominal angina and under oral anticoagulant therapy.

Drug Therapy, Combination↗
PubMed1985

Combined dys-form of homozygous factor XI deficiency and heterozygous factor XII deficiency.

A 12-year-old girl with lifelong hemorrhagic episodes was found to have both a dys-form of homozygous factor XI deficiency and heterozygous factor XII deficiency. The heredity of the coagulation defects was confirmed by family studies. Severe bleeding after dental surgery occurred in spite of replacement therapy and local measures including fibrin glue. Our findings suggest that the risk of bleeding in patients with homozygous factor XI deficiency must not be underestimated and that the most effective measure is the transfusion of sufficient amounts of fresh frozen plasma until at least the 5th postoperative day.

Blood Transfusion↗
PubMed1984

ATP-dependent spectral response of oxonol VI in an ATP-Pi exchange complex.

Energy transduction in an ATPase complex (complex V) has been studied in two reactions catalyzed by this system, i.e., ATP-dependent spectral shift of oxonol VI, and ATP-Pi exchange activity. Aurovertin alone inhibits 50% of the oxonol shift at 2 microM, and no further inhibition occurs at up to 12 microM. In combination with even weakly effective uncouplers, 4 microM aurovertin fully abolishes the oxonol response. No such effects are observed in the presence of oligomycin and uncouplers. No pH gradient is detectable by quenching of 9-amino-6-chloro-2-methoxyacridine; and nigericin is without effect on the oxonol response. Valinomycin is inhibitory even in the absence of added potassium, due to ammonium ions introduced during the purification steps. Thiocyanate inhibits the dye response by only 10-27%, depending on the preparation. The extent of the oxonol response depends on the ATP/ADP ratio rather than the phosphorylation potential. The dye response in the ATPase complex is 4-7-times less sensitive to bile salts than in submitochondrial particles. The inhibition by cardiolipin can be reversed by the addition of phospholipids. The possibility is discussed that the oxonol response in the ATPase complex reflects, at least in part, a more local, ATP-dependent and energy-related process.

Animals↗
PubMed1978

[Effect of various plasma expanders on blood group serological study results].

Plasma expanders can disturb in serological blood typing tests to varying amounts. In order to avoid possibly fatal errors in index reading, it is, therefore, necessary when demanding this type of examination to inform about any infusion of plasma expanders carried through before the blood test and to take it into consideration.

Dextrans↗